Step #4:

Suspend your rusty part from the pipe or stick with wire, submerged, making sure it does not touch the steel basket lining the bucket. Do not use copper like I did. Use steel wire, the same as for the cage. Make sure the two poles ( positive and negative ) never touch.

Make sure your work area is well vented! Unplug your 12-volt battery charger. Set it to about 2 amps. Hook the positive (red) lead to the bucket basket and the negative (black) lead to the rusty part lead. Plug the charger in and look at the meter; it should be drawing about 2 amps. If it is a lot more or things are smoking, UNPLUG! The part will slowly start fizzing. When it stops (a couple of hours later, depending on the part), unplug your charger and remove your part. Clean the black slime off of it and paint or oil it to protect it.

The water is NOT toxic; it is safe to pour down a drain. It is just soap and steel. The process should have removed any loose paint also.

Step #5:

Conclusion

This can be made from scrap materials and recycled or re-used when finished. It is very simple to make when you understand the simple process, You can improve on your next one! It will not last, the cage is a consumable. Build it custom for each project, do not over-think this. K.I.S.S.

I was just researching this to clean up some old milling and lathe parts, and from what I can tell copper is fine, but you don’t want it touching the water. Only the steel should be submerged.

I imagine with copper’s lower resistance the current will preferentially bypass the steel, killing off the electrolytic effect, and rapidly corroding the copper away. This is only suitable for ferrous metal, if I read right.

I’m not sure about the material for the cage, but everything I read indicates that you want to stick with steel. Other examples I see use a steel clamp or chain to suspend the item to be cleaned. As long as they don’t touch the electrodes I think you’re ok.

Stainless steel is mixed with chromium, and while it’s consumed more slowly than regular steel, this reaction would steel create chromate and hexavalent chromium. These are pretty horrible things, so don’t do it. Hexavalent chromium dumping is what Erin Brockovich fought against. Cancer is bad, mmkay?

stan the toolfool

Yes, more like a cage, all parts of the rusty item need to be “line of sight” with the cage, but not touching. This wire is a consumable and is not graded for neatness! Everything but the battery charger can be junk from the scrap pile. If you find a working charger there that’s great too!

Matt Park

Oh yeah, I remember that “Chrome 6″.

I suppose you could also use a similar process, by making the cage out of zinc and swapping the charge to lightly galvanize the part for long term storage? Though I guess oil would work about as well…

Regardless, this is a sweet guide, and I look forward to trying it.

stan the toolfool

I hope you didn’t copper plate your plane, it will turn green. Use steel wire only!

Plognark

Did a successful test run with some old rusty nuts and bolts. I had to use a deep cycle 12 volt battery for the power source; the power supply I got has some finicky circuitry that I haven’t gotten figured out yet.

Plognark

Your results sound about right. You may not notice anything with the copper yet, but I did dig up some more info on it:

“It is important that any copper connector to the anode not touch the solution. If it does, copper will oxidize to cupric ion, Cu++. The connector will be destroyed. Most of the copper ions formed should precipitate as copper carbonate or copper hydroxide, but if any of this dissolved copper reaches the cathode it will be reduced to copper metal on the iron object. Its presence will promote rapid rerusting.”

If I understand the chemistry right most of the copper will settle out, but any of it that manages to swirl around and hit the iron cathode will help oxidize the iron all over again.

Robert D.W. Schilbach

Be VERY careful of “washing soda”. This sometimes describes Sodium Hydroxide,which is a VERY powerful alkali Treat it with the same caution that you would use for a concentrated acid!
BAKING POWDER (sodium bicarbonate) works just as well, and is innocuous. Other than that use phosphoric acid. BE CAREFUL! failing that use coca-cola, ‘cos there’s phosphoric acid in that ! Don’t believe me? Try putting a copper coin in it and see what happens!
Also, the standard “trickle chargers” aren’t up to it. They burn out. Since normally they put out 2 or 4 amps or so. My setup takes up to 40 amps.
Using an arc welder is DANGEROUS—– just see the firewoks in the liquid, sometimes!

Phil Wood

To clear up confusion regarding the electrolyte the term washing soda as used here refers to sodium carbonate, which is sold with laundry detergents. Not sure why, but I read somewhere that washing soda is preferred over bicarb. Some chemical thing, I guess.